... 1.Heated 2.ISO9001 quality guaranteed 3 order one-stop service All parts of 520 roller chains are by special surface treatment On ... hardening Dear customers, motorcycle roller chain 520 is for motorcycle TRANSMISSION SYSTEM.Roller chain Quality is vital for riding safety. As motorcycle ... is 25000~30000kms, which is strict quality test result. 1.Motorcycle Roller Chains:25H (04CH), 415, 415H, 420, 420H, ...